odourless stop and fix

[numnutz]

I have just started using odourless stop and fix for my film processing. I found on coming to use the stop bath that the surface of the solution in the bottle was covered in what looked like a film of mold - similar to that you sometimes get with some alternate process chemicals.

I filtered the solution and used it and the results seemed OK. Does this usually happen? and can I prevent it by using a drop of formalin / formaldehyde?

I use 200ml of working solution for film so I realise I may be accused of being tightfisted in using it a few times, but it has got an indicator built in. I haven't used the fix yet, would I get a similar problem with that?

Chemistry is:
Fotospeed SB50
Fotospeed FX30
Used in a Paterson orbital processor 4 x 5x4 sheets of film

nn

[Dave miller]

I've experienced the mould on stop bath working solutions, it's one reason I stopped using it and reverted to a couple of plain water rinses between dev and fix.

[Les McLean]

I agree with Dave, I've used plain water as a stop bath for both film and prints for many years. It's effective, there is no risk in damaging the film and it's not expensive.

[Mike O'Pray]

If I have understood your process correctly you use only 200ml of stop bath which is less than even the Jobo or Durst tanks need to cover the reel(250mls).

While inversion may do the job with 200mls, it might be sensible to use enough to cover the reel.

I too switched to water rinses instead of stop several years ago with no ill effects.

It works well and is even cheaper than stop. So for a Scotsman that's two reasons to use it :

Mike

[Bob]

Odourless stop is generally made from citric acid. It does seem to promote growth after a while. Just buy citric acid powder in bulk and use it at 20g/litre and dispose of it down the drain afterwards - it is entirely harmless.

[Martin Aislabie]

I have never had a problem with odourless Stop growing "freinds"

However, I did have a problem with the Fotospeed odourless Stop - I could smell it - although a low intensity smell I could easly detect it and found it highly unplesant - so much so that I threw most of it away

I found the Ilford Stop to be less unplesantly smelly.

YMMV

As for Fix - I just love the smell of regular Fix - its what real darkrooms should smell like - but may be that it just me being a bit odd

Martin

[Trevor Crone]

I too just use a plain water rinse as a 'stop' bath for film but use a weak Fotospeed odourless stop bath for prints which I throw away after each session.